CO2 hydrogenation to liquid hydrocarbons via modified Fi scher Tropsch over alumina supported cobalt catalyst s : effect of operating temperature, pressure and potassium loading

Abstract: The effect of promoting 15%Co/Al2O3 catalyst with potassium on CO2 hydrogenation to longer-chain hydrocarbons was investigated. The catalysts used in this study were synthesized using an incipient wetness impregnation of the support with nitrate solutions. All catalysts were supported on γ-alumina and promoted with potassium (0 – 8%). The synthesized catalysts were characterized by XRD, BET, XPS, TPR and CO2-TPD analyses. The catalysts were evaluated for CO2 hydrogenation using a fixed-bed tube reactor. The CO2 conversion was found to increase with both the reaction temperature and pressure. The TPR data revealed that potassium limited the reduction of the catalyst, decreased the selectivity to methane and increased the selectivity to C2+ hydrocarbons. The maximum C2+ yield of 10.2%, with CO2 conversion of 42.3%, was obtained when 6 wt.% of potassium was added to the catalyst. It is believed that during the CO2 hydrogenation process over the catalysts that were promoted with potassium, CO2 is first converted to CO via reverse–water–gas–shift reaction, followed by subsequent hydrogenation of CO to hydrocarbons

Fischer-Tropsch synthesis over unpromoted Co/ɣ-Al2O3 catalyst: effect of activation with CO compared to H2 on catalyst performance

Abstract : The effect of activating Co/Al2O3 catalyst by diluted CO or H2 on catalyst performance for Fischer-Tropsch reaction was investigated. The catalyst was prepared by incipient wetness impregnation of the support and characterized using BET N2 physisorption, SEM and XRD analyses. The reduction behavior of the catalyst in presence of CO and H2 individually was evaluated using TPR analyses. The data reveal that CO activates Co/Al2O3 catalyst at a lower temperature than H2 and produces a catalyst with higher rate for liquid product formation. It also leads to higher methane selectivity probably due to some cobalt carbide formation

Catalyst deactivation rate during hydrogenation of CO2 to longer chained hydrocarbons over 6 wt.% potassium-promoted Co/Al2O3 catalyst

Abstract: Please refer to full text to view abstract